Comparative ultrastructural morphometrical studies in acute leukemia.

Four hundred paramyeloblasts (from meyloblastic, promyelocytic, monoblastic and lymphoblastic types), isolated from peripheral blood of untreated leukemia patients, were studied by planimetric ultrastructural morphometry. The data of 19 parameters for these four paramyeloblastic types were compared with statistical methods. More central "scattered" heterochromatin was found from this morphometric investigation, i.e. early prophases in the lymphoblastic type of acute leukemia (these cases are more sensitive to therapy). The absolute mean values of the areas of whole cells, areas of the nucleus and nucleolus, areas of the heterochromatin and other indices show that different cell clones will undergo leukaemic transformation.